Filled and imitation cheese products using a vegetable fat in place of butterfat are well-known. Several major factors have influenced their greater acceptance. For one, a vegetable fat is less expensive than its butterfat counterpart. Another factor has been technical improvements in the filled and imitation products and components employed in their manufacture. For instance, functional lipid systems capable of meeting almost any specification are now available.
A truly imitation cheese offers several further advantages over a filled product. Its manufacture avoids the need for maintaining acid-producing micro-organisms conventionally employed in the cheese-making process. Also avoided are the formation of whey as a by-product and the accompanying need for separation and disposal of the same. In addition, the process for the production of an imitation cheese can be semi-continuous or continuous whereas processes for production of natural and filled cheeses of necessity are carried out on a batch basis.
From a nutritional point of view, the filled and imitation products may be of the same quality as their corresponding natural products.
Whereas a large number of filled cheese products exist on the market today, those truly imitation cheese products which have been developed have been more in the nature of soft cheeses, imitation sour creams or sour cream whips, cream cheeses and cottage cheeses. One such product is described in the Elenbogen U.S. Pat. No. 3,397,995 and is characterized as a cream cheese spread. In this patent, lactic acid is incorporated directly into a composition comprising about 15 to 40 percent by weight fat having a ratio of polyunsaturated to saturated fats in the range of about 3:1 to about 9:1, the composition also having about 5 to 15% of a phosphoprotein solid, such as an alkali caseinate, and an amount of a stabilizing vegetable gum, the remainder being water. The patent discloses that optionally an amount of an emulsifier such as a mono- and diglyceride or sorbitan ester of a fatty acid may be used.
One problem experienced with the manufacture of acid-set cheese is the production of an uneven product of varying quality. For instance the Little U.S. Pat. Nos. 3,378,375 and 3,792,171, state that the acid overacidifies portions of the casein-containing product causing premature precipitation of these portions while other portions which are the last to be acidified form a large, hard, coarse curd. By comparison, when bacteria cultures are employed, the acid is formed slowly, uniformly and in situ so that the acidity of the milk product lowers slowly and uniformly. It is stated that even when concentrated acids are added slowly and under proper conditions of temperature and mixing, a consistently uniform product is difficult to obtain. Applicants' own observation is that separation of oil from the formed product, referred to as oiling-off, can readily occur at the end of mixing in the acid-set manufacture of imitation cheese.
With regard to mozzarella cheese and other harder cheeses, those new products which have been developed can be more readily categorized as filled cheeses. Prior U.S. Pat. No. 3,579,354 to Kasik et al describes an elastic cheese product which is useful as a substitute for mozzarella cheese prepared from an aqueous dispersion comprising 1 to 15% sodium caseinate and up to 30% butterfat. The fat sodium caseinate mixture is innoculated with a starter and then is further innoculated with micrococci and allowed to ferment aerobically until the system becomes elastic and plastic in consistency. Acidification then takes place to coagulate the product, the acidification being to a pH of about 5.2 to about 3.2.
The product of the patent is not a true imitation product, and is unduly expensive because of the large amount of butterfat employed. The product also suffers from the disadvantages normally associated with processing of a natural product.
U.S. Pat. No. 3,922,374, issued to Bell et al, discloses a non-dairy imitation cheese resembling pasta filata, cheddar and pasteurized process American-type cheeses. The cheese is made by the in-situ forming of calcium or sodium caseinate in a formulation containing water, acid and casein hydrochloride, to which sodium hydroxide to calcium hydroxide is added. Fat is added to the formulation plus other ingredients. The final product contains sufficient acid to achieve a product pH typical for processed imitation or filled products, of about 5.1. It is stated in the patent that sodium caseinate is unsatisfactory as the protein in imitation mozzarella cheese exposed to severe high temperature conditions (such as on a pizza). The reason given is that an imitation cheese using sodium caseinate instead of calcium caseinate tends to burn and puff when exposed to high heat. Examples in the patent which relate to the preparation of a mozzarella-type cheese employ only calcium caseinate, formed in situ. The patent describes the use of certain inorganic salts, such as disodium phosphate and sodium aluminum phosphate, referred to as emulsifying salts, but only in cheddar and pasteurized process American cheeses. The examples for mozzarella cheese do not employ such salts.
U.S. Pat. No. 2,148,593, Teller et al, also describes the conventional practice in the cheese art of employing an emulsifying salt in the cheese processing steps; for the expressed purpose of preventing separation of casein and fat constituents. No mention is made of mozzarella cheese or organic emulsifiers.
In this regard, mozzarella cheese is a different cheese. It can be characterized as a fresh, high moisture cheese having a relatively bland flavor. The cheese is rubbery in nature, that is, provided with a high degree of stretch, is hard so that it can be grated into flakes, and browns when cooked. It is frequently combined with other foods, for instance, tomato sauce in the preparation of pizza, and in this regard should have good melt-down characteristics providing a continuous fused layer when baked. Further, the cheese should be firm, versus soft, and smooth in texture. Reference can be had to prior U.S. Pat. Nos. 3,531,297 and 3,692,540 for a further description, incorporated by reference herein, of properties desired of pasta filata cheeses.
Prior copending application Ser. No. 752,260 now U.S. Pat. No. 4,075,360 describes an improved mozzarella-type cheese which is obtained by employing as the basic ingredients about 15-35% of a caseinate of which at least 70% is sodium caseinate, about 15-30% of a low melting point hydrogenated vegetable oil, a small amount of a calcium containing salt such as calcium chloride, and an amount of an edible acid, preferably lactic acid, the remainder being water (about 45%) and small amounts of flavor, preservative and other ingredients. A critical feature of the prior application lay in the use of at least about 70% sodium caseinate, as the caseinate component; sufficient acid to provide a final pH of the product of about 5 to 6; and a calcium ion containing salt.
Sodium caseinate offers the advantage, over calcium caseinate, that it provides a higher degree of stretch, a characteristic of mozzarella cheese. However, as disclosed in the Bell et al U.S. Pat. No. 3,922,374, the use of sodium caseinate as the protein tends to cause burning and puffing when the imitation cheese is used on pizzas. It is suggested that by contrast the use of calcium caseinate does not cause such burning and puffing. It is surmised that the use of calcium caseinate probably causes the formation of a discontinuous surface which allows vapors to escape. Although this is better from the point of view of puffing and burning, the calcium containing product, being less rubbery or stretchy, does not make as good a mozzarella cheese for such applications as pizzas.
The advance of said copending application resided in the discovery that by limiting the acid content of the product formulation, and employing a calcium containing salt in the formulation, the melt-down properties of the cheese were improved to reduce the formation of large bubbles and burning during cooking. At the same time, the desired stretch properties characteristic of a mozzarella cheese were retained.
For purposes of the present application, a mozzarella-type cheese formulation shall mean any formulation for the manufacture of an imitation pasta filata cheese.
The disclosure of the prior application Ser. No. 752,260 is incorporated by reference herein.